First WFI Appointment. Problems Attending.

I am in the WRAG. I have just received the letter asking me to attend my first wfi appointment.
I am really scared, because I don't think I will be able to go. I suffer from depression and agrophobia. I never go out on my own. My brother who lives quite a way from me takes me to any appointments I can't avoid going to.
However, my brother works and can't always get time off to take me. My appointment is 13th May. I called my advisor and explained my situation. She has told me to see if I can get anyone else to come with me. If I can't I have to call her back a few days before my appointment.
I asked what would happen if I can't get anyone to come with me. She said she doesn't know. They will have to take it to the next stage.
My brother says he will not be able to come with me, as he has had a lot of time off work lately. What is going to happen?
I did ask the advisor if I could do the interview on the phone. But she said that would not be possible.
I'm not being awkward. I just won't be able to go on my own. My brother is the only one that I have to help me, as I live miles away from family and friends. As my brother is unable to help me this time. What will happen to me? I am so scared.